Hydraulic cushion for sheet-metal presses



April 3, 1928. I 1,664,487

E F. J. RODE HYDRAULIC CUSHION Foa SHEET METAL PRESSES Filed April 21 1927 Y i l lA -xilhllh 'Iullll A x2 20I i Illl lli

Patented Apr. 3, 1928.

UNm-:D s'raxrlzs` 1,664,487 PATENT OFFICE.

.FRIEDRICH J. RODE, 0F CHICAGO, ILLINOIS, ASSIGNOB '10 MARQUETTE TOOL m.

COMPANY, 0F CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

HYDRAULIC CUSHION FOR SHEET-METAL PRESSES. v

Application ledApl-il 21, 1927. Serial No. 185,490.

This invention relatesto improvementsin hydraulicl cushions particularly adapted though not necessarily limited in its use for sheet metal presses in which the metal is shapedby means of co-operating dies, one of which dies is reciprocable toward and away from the other, the work being clamped or held by means of a blank or work holding element that co-operates with lthe reciprocable die member, the blank or ing element.

A further object is to provide in acushion of this character improved means for returning the liquid to the pressure side of the piston at a predetermined time in the. cycle v of operation of the press, and improved means for varying at will the time at which the said liquid is thus returned.

T o the attainment of these ends and the accomplishment of other new and useful objects as will appear, the invention consists inthe features of novelty in substantially the construction, combination and arrangement of the lseveral parts hereinafter more fully descr/ibed and claimed and shown in the accompanying drawing illustrating this invention, and in which The figure is a view partly inside elevation, partly broken away and partly lin section of a sheet metal press having an hydraulic cushion constructed in accordance with the principles of this invention applied thereto.

Referring more particularly to the drawing the numeral 10 designates generally the bed or bolster plate of a sheet met-a1 press, 11 the uprights, 12 a reciprocating ram'to which a die 13 is connected and which ram is connected by means of links 14 to a crank shaft 15, and which shaft is rotated in any suitable manner and from any suitable source of power, not. shown. v

' Mounted upon the bed plate 10 is a die 16 with which a blank or work holding member 17 co-operates and encompasses. The member 17 is supported by means of suitable pins 18 passing loosely through the bed plate`10 and engaging and resting upon a pad or pin plate 19.

The pins 18 are of such a length that the upper surface of the member 17 will be normally held substantially flush with the upper surface of the die 16 to support the work 20.

All of the above referred to parts are of the ordinary and well known construction.

Supported below the bed plate 10 is a support 21 which is prefera 1y arranged within a pit 22 and mounted upon thesupport 21 is a cylinder 23 in which a piston' 24 reciprocates. A piston rod 25 connected with the piston 24 passes through a suitable stuing .box 26 in the top of the c linder 23, and is secured by means of suita le fastening devices 27, to the pad or pin plate 19. A vent opening 28* may be provided in the cylinder 23.

A cylinder 28 telescopes over the cylinder 23 and is preferably of an internal diameter considerably greater than the external diameter of the cylinder 23 and is open at its bottom as at 29. A piston 30 is secured to the cylinder 23 and co-operates with the cylinder 23 so that the end of the cylinder 23 also operates as a part of the piston.

The piston rod 25 passes through a suit'- able stuing box inthe end of the cylinder 28 and a member: 32 may be secured to the open end of the cylinder 28 as a. safety device to prevent the cylinder 28 from rising too far with respect to the cylinder 23.

The cylinder 23 is provided with an opening 33 to which a pipe 3i is connected and which pipe also has communication with an opening 35 through the piston 30.

A valve 36 controls the .o ning 33 and this valve is held in its seat y means of a resilient element 37 in the form of a spring los when the valve 36 is unseated will flow through the pipe 34 to be discharged into the cylinder 28 vabove the piston 30 thereby causing the cylinder 28 to rise.

When the cylinder 28 is lowered, in a manner to be Vset forth, the liquid will flow from between the piston 3() and the end of` the cylinder 28 through an opening 39 into a pipe 40 and back into the cylinder 23l plied through a suitable inlet opening 43l controlled by a suitable valve (not shown). Thus it will be seen that when the piston 24 is lowered during the formation lor shaping of the work the liquid in the cylinder 23 can find its way from the cylinder only through the passage23, and as the valve 36 is set to operate at only a predetermined pressure, the liquid in the cylinder 23 will act to resist the movement of the piston 24 in vone direction and until the pressure of the liquid in the cylinder 23 overcomes the stress of the spring 37 to open the valve 36. At this time the liquid will ilow through the pipe 34 to raise the cylinder 28 with respect to itsstationary piston 30.

When the cylinder 28 is forced downwardly the liquid will be forced out of the opening 39 through the pipe 40,- past the valve 42 and through the opening 41 into the cylinder 23, to raise the piston 24 and thereby restore the pad or pin plate 19.

As a means for lowering the cylinder 28 to force the liquid therefrom a resilient element 44, preferably in the form of a-spring, any number of which may be provided, is provided and is supported by means of a ormation or shoulder 45 carried by the cylindex' 28.. A rod or link 46 passes through the spring 44 and is rovided with a washer or shoulder 47 whic operates -against the other end of the spring 44.

This rod or link is pivotally connected as at 48 to one end of a lever 49 that is pivotally mounted intermediate its ends as at 50 to a fixed or stationary support 51.

Connected with the other end of the leverv is an antifriction roller 52.

As the cylinder 28 is raised the spring 44 and rod or link 46 will also be raised, causing the lever 49 to rockabout its pivot 50 to lower the end ofthe lever carrying the antifriction roller from the position shown in the figure. This operation will prevent the 'creating of any 'energy in the resilient eleyments 44.

In order to restore the cylinder 28 it is necessary to store or create energy in the springs 4 4 by compressing the same and this is accomplished preferably by means of a cam 53 which is adj ustably secured by means of suitable fastening devices 54 to a rod or bar 55.

This bar 55 is connected to any suitable movable portion of the press, here shown as the ram 12, and in the present form of the invention passes loosely through the bed plate 10.

Assuming `the parts to be in the position shown in the iigure, the operation 'is as follows. i

When the ram 12 Tdescends the cam 53 will descend, causing the high portion of the cam 53 to pass out of engagement with the anti-friction roller- 52 and thereby position the low portion of the cam adjacent the roller 52. This will occur just at the time when the die 13 contacts with the work 20.

A further lowering movement of the ram 12 in the same direction will cause the pin y:plate 19 to be depressed through the medium of the member 17 and pins 18, thereby forcing the piston 24 downwardly in the cylinder 23. When a predetermined pressure has been obtained on the liquid in the cylinder 23 the valve 36 will be opened and the piston 28 will be elevated in the manner described.

At this point in the operation and as the low portion of the cam 53 is adjacent the` roller 52 or end of the lever 49, the lever will rock about its pivot and no stress will be created in the spring 44.

When, however, the ram 12 starts to aseend from this position, the high part of the cam 53 will contact with the roller 52 and thereby rock the lever 49 in the opposite. directionabout its pivot, thereby compressing the springs 44, and the energy thus stored in the springs will force the cylinder 28 downwardly, causing the liquid between the piston 30 and the end of the cylinder 28 to be forced through the opening 39, pipe 40 and opening 41 into the cylinder 23 on the pressure side of the piston v24 to restore the A piston 24 and the pin plate 19.

While the preferred form of the invention has been herein shown and described, it is Ato be understood that various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the scope of the claims,

without ldeparting from the spirit of this invention.

, What is claimed as new is 1. In a sheet metal working press a pressure pad, an hydraulic cushion for resisting the movement of said pad in one direction and embodying cylinder and piston members one of which members operates upon the pad, anadditional and movable cylinder, a stationary piston co-operating with the latter, a conduit for leading liquid from the pressure side of the lirst said piston between the said movable cylinder and stationary piston, variable resistance means for controlling said conduit, a second conduit for leading the liquid from between the stationary piston and movable cylinder back to the pressure side -of the first said piston to restore the latter, means for controlling 'the last said conduit, a normally inactive resilient element carried by the movable cylinder, a lever mounted upon a fixed pivot and operableupon said resilient element, and means connected with a movable part of the press for operating the lever at a predetermined time in the cycle of operation of the press to create energy in the said resilient element to restore the said movablecylinder.

2. In a sheet metal working press a pressure pad, an hydraulic cushion forresisting the movement of said pad in one direction and embodying cylinder and piston members one of which members operates upon the pad, an additional and movable cylinder, a stationary piston co-operating with ,the latter, a conduit for leadingl liquid from the pressure side of the first said piston between the said movable cylinder and stationary piston, variable resistance means for controlling said conduit, a-second conduit for leading the liquid -from between the stationary piston and movable cylinder back to the pressure side of the first said piston to restore the latter, means for controlling the last said conduit, a normally inactive resilient element carried by the movable cylinder, a lever mounted upon a Afixed pivot and operable upon said resilient element, means connected with a movable part of the press for operating the lever at a predetermined time in the cycle of operation of the press to create energy in the said resilient element to restore the said movable cylinder, and means for controlling at will the time of operation of the last recited means.

3. In a sheet metalF press a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction and emn bodying a staticnary cylinder, a piston therefor, a movable cylinder telescoping over the first said cylinder, lthe latter forming a portion of a piston for the movable 'c'ylinder, a conduit for leading the liquid from the firstY cylinder into the second cylinder, variable resistance means for controlling the conduit, a second conduit for leading the liquid back to the first said cylinder to restore the piston in the latter. a resilient element carried by the movable cylinder, a lever pivoted to a xed support, one end of the lever operating upon the resilient element, and means connected with a movable part of the press and operable upon the lever to create ener rin the resilient element at a predetermlned time inthe cycle of operation of the press t'o restore the said movable cylinder.

4. In a sheet metal press a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction and embodying a stationary cylinder, a piston therefor, a movable cylinder telescoping over the first said cylinder, the latter forming a portion of a piston for the movable cylinder, a conduit for leading the liquid from the first cylinder into the second cylinder, variable resistance means for controlling the conduit,

lvarying at will the time of operation of the last said means upon the said lever.

5. In a sheet metal press a pressurev pad, an hydraulic cushion for resisting the movement, of .the pad in one` direction and embodying A'a stationary cylinder, a piston therefor, a movable cylinder telescoping over the first said cylinder, the latter forming a portion of a piston for the movable cylinder, a conduit for leading the liquid from the "first cylinder into the second cylinder, varia-- ble resistance means for controlling the conduit, a second conduit for leading the liquid back to the first said cylinder to restore the piston in the latter, a resilient element carriedby the movable cylinder, a lever pivoted to a fixed support, an operative connection between the lever and said resilient element for compressing the latter to restore the movable cylinder when the lever is rocked in one direction, and means connected with a. movable part of the press for thus rocking the lever at a. predetermined time in the cycle ofoperation of the press.

6. In a-sheet metal press a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction and embodying a stationary cylinder, a piston therefor, a movable cylinder telescoping over the first said cylinder, the latter forming a portion of' a piston for the movable cylinder,

a conduit for leading the liquid from the rst cylinder into the second cylinder, variable resistance means for controlling the c onduit, a second conduit for leading the l1qu1d back to the first said cylinder to restore the pisl ton in the latter, a resilient element carried by the movable cylinder` a lever pivoted to a fixed support, a link connected with the lever and passing through said element to compress "the latter when the lever is moved in one direction to 'create energy to restore the movable cylinder, and means connected with a movable part of the press for thus rocking the lever at a predetermined time in the cycle lever operating upon the resilient element, of operation of the press. and means connected with a movable part 7. In a sheet metal press a' pressure pad, of the press and operable upon the lever to an hydraulic cushion for resisting the movecreate energy in t e resilient element at a ment of tho pad in ono direction andy empredetermined time in the cycle of operation bodying a stationary cylinder, a piston of the press to restore the said movable cyltherefor, a movable cylinder telescoping over inder. the first said cylinder, the latter forming 10- In a Sheet metalworking press a pres-l a portion of a piston for the movable cylineule Pd, 2111 hydraulic CuShlOil OI' leslsbder, a conduit for leading the liquid from lng the mOveinent of the pad in o ne directherst cylinder into the second cylinder, J'21011 and embodying a stationary piston and variable resistance means for controlling the a movable cylinder co-operating therewith, conduit, a second conduit, for loading tho a resilient element movable with the cyhnder liquid back to the first said cylinder to rcand normally inactive with respect to the store the piston in the latter, a resilient elecylinder, means for forcing a liquid between ment carried by the movable cylinder, a lever the cylinder and piston to move the former, pivoted to a fixed support, an operative a member operable upon the resilient eleconnection between the lever and said rement to create energy therein, a lever pivsilient element for compressing the latter to `otally mounted upon a fixed support, one restore the movable cylinder `when thelever end of the lever operating upon said memis rocked in one direction, means connected ber, and means connected with a movable with a movable part of the press for thus part of the pressand operable upon the rocking the lever at a predetermined vtime lever at a predetermined time in the cycle in the cycle of-operation of the press, and of operation of the press to render the said means for varying at will'the said time of member active with respect to said resilient Aiperation of the last said means upon the element, whereby the cylinder will be moved ever.

8. In a sheet metal press a pressure pad, tween the cylinder and piston. an hydraulic cushion for resisting the move- 11. In a sheet metal working press a presment. of the pad in one direction and einsure pad, an hydrauliccushion for resisting bodyingastationary cylinder, a piston therethe movement of the pad in one direction for, a movable cylinder telescoping over the and embodyin a -stationary piston and a first said cylinder, the latter forming a por- -movable cylin er co-operat-in therewith, a tion o f a piston for the movable cylinder, a resilient element movable witlri the cylinder conduit for leading the liquid from the rSt. and normally inactive with respect to the cylinder into the second cylinder, variable cylinder, means for forcing a liquid be-Y resistance means for controlling the conduit, tween the cylinder and iston to move the a second conduit for leading the liquid back/ former, s. member opera le upon the resilto the irst said cylinder to restore the plS- ient element to create energy therein, a lever ton`in the latter, a resilient element carried pivotally mounted upon a fixed support, one by the movable Cylllllel'a e lever Plvetellte endof the lever operating upon said mema fixed support, an operative connection bebei', means connected with a movable part tween the lever and said resilient element for of the press and operable upon thc lever at4 COmPI'eSm-I the lelilel t0 restore tl-1em0v -a predetermined time-in the cycle of operalgle C lllldel When the lever 1S rocked 111 O Ile tion of the press to render the said-member dll'eetlen, and e, @am 'devlee Connected W 1tl1 active with respect to said resilient element, e movable parl' 0f the Pres? for tllUS IQekmg whereby the cylinder will be moved in a the level' all a Plelelemllned lilme 111 the direction to force the liquid from between Cycle 0f Operai/1011 0f the Pressthe cylinder and piston, and means for va- 9. In a sheet metal PI'eSS Pressure Pad, g at will the time in theloperation of all llyfll'alllc Cuslllon for l'eslsl'llllg the move' he press at which the last said means will ment. of the pad in one direction andv einoperate upon the said member, .bodying a stationary cylinder, a plStOn there- 12. In a sheet metal working press a presfor, a movable cylinder telescoping over the Sure pad, an hydraulic cushion for resistlll'st Sad eylmdela the letter folmllg P01' ing the movement of the pad in one directll-ll 0f a plslen fol' the movfjlble Cylllldel', elle tion and embodying a stationary piston and end of the Said movable cylinder being Open, a movablel cylinder co-operating therewith, .a' Conduit for .leading the llqllld from the a resilient element movable with the cylini'rst cylinder into the second cylinder, vader and normally inactive with respect to riable resistance means for controlling the the cylinder, means vfor forcing a, liquid bec oiid u1t, a second conduit for leading the tween the cylinder and piston to move the liquid back to the first said cylinder to reformer, a member operable upon the resilstore the piston in the latter, a resilient eleient element to create energy therein, a lever ment carried by the movable cylinder, a lever pivotally mounted upon a fixed support, one pivoted to a fixed support, one end of the end of thelever operating upon said memin a direction to force the liquid from beiio ber, and a cam device connected with a movable lpart of the press and adapted to engage androck said lever at a predetermined time in the cycle of operationI of the press to` create energy in the said resilient element to restore the cylinder and thereby force the liquid from between the cylinder and piston.

13. In a sheet metal working press a'pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction, a resilient element carried with the piston and normally inactive with respect thereto, means for forcing liquid between the piston and cylinder to move the former, a member passing through said element and 'co-operating with the resilient element support for compressing the element to store energy therein to restore the piston and thereby force liquid from between the piston and cylinder, a lever pivotally mounted upon a txed support, one end of the lever being connected with the said member, and means responsive in its'movement to the operation of a movable part of the press for rocking said lever at a predetermined time inthe cycle of o eration of the press to render the said mem er active.

14. In a sheet metal working press a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction, a. resilient element carried with the piston and 'normally inactive with respect thereto,

means for forcing liquid between the piston and cylinder to move the former, a member passingthrough said element and co-operating With the resilient element support for compressing the element to store energy therein to restore the piston' and thereby force liquid from between the piston and cylinder, a lever pivotally mounted u on a fixed support, one end of the lever eing connected with the said member, means responsive in its movement to the operation of a movable part of the press for rocking said lever at a predetermined time in the cycle'of operation of the press to render the said member active, and means for varying at will the time in the operation of the press at which the last recited means will operate upon the said lever.

In testimony whereof I have signed my -v name to this specification, on this 15th day of April, A. D. 1927.

. FREDRICH J. RODE. 

